drive_replies_update

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

The description adds meaningful behavior beyond annotations: it discloses that the reply's content is overwritten and the previous text is not retained, and that only the reply's author can update it (API rejects otherwise). While annotations already flag destructiveHint=true and readOnlyHint=false, the description enriches this with concrete consequences and an authorization constraint. It does not cover rate limits or error details, but the key behavioral traits are disclosed.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is three sentences, each carrying distinct information: the main action, the destructive consequence, the authorization rule, and the non-capability with an alternative. It is front-loaded with the core purpose and has zero filler. Every sentence earns its place.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Given 5 parameters (4 required), full schema coverage, and no output schema, the description covers the critical operational details: the overwrite behavior, the author-only restriction, and the limitation regarding action changes with a routing hint. It does not mention return format (no output schema, so not required) or potential failure modes beyond the author rejection. This is a complete picture for an agent to safely invoke the tool.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100%, so all five parameters are already documented in the input schema (e.g., content: 'New reply text'). The description adds no additional parameter-level detail beyond what the schema provides. It does reiterate that content is the new text, but this is redundant. Baseline 3 is appropriate given the high schema coverage.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description opens with a specific verb+resource ('Change the text of an existing reply'), immediately distinguishing it from sibling tools like drive_replies_get or drive_replies_delete. It also explicitly contrasts with drive_replies_create by stating it does not support changing action, so an agent can clearly tell when to pick this tool over alternatives.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description provides a clear exclusion and alternative: 'Does not support changing action — use drive_replies_create to resolve/reopen.' This tells the agent when NOT to use this tool and routes to the correct sibling. However, it does not explicitly state the general condition for using this tool (e.g., 'use to modify reply text'), though that is strongly implied by the purpose statement.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.